Web says that there is a 15 day trial but my Studio is in community mode since the install.
What is the procedure to get the trial?
You have probably installed it before. Otherwise it would show a trial registration dialog.
No I haven't installed it before.
You should have seen this dialog after running Radzen Blazor Studio for the first time.
After registering and entering the trial code it starts 15 day trial mode.
How do U get a trial code?
Can you please check in your system if an account was created using the same email address as for this forum user account?
It seems you are using a different product than the one specified originally. In Radzen Studio you can skip the trial registration and enter community mode directly. I am afraid you can't switch back to trial after doing this.